Blue sulfur dye and process of making same.



I UNITE STATES ATENT (Denice,

I RICHARD HERZ, OF FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOR TO LEOPOLD CASSELLA 61; 00., OF FRANKFORT-ON-THE-MAIN, GERMANY.

BLUE SULFUR DYE AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 709,151, dated September 16, 1902.

Application filed February 3, 1902. Serial Nor 92AM). (N0 specimens.)

lIlOl'ClrII scale, I have made the discovery that the hitherto-unknown para amidotolyl para oxyphenylamin of the constitution may be obtained quite easily and almost quantitatively by reducing the product of simultaneous oxidation of para amidophenol and ortho toluidin. I have further discov ered that whereas the direct-dyeing blue sulfor colors which have been produced from para amido para oxydiphenylamin cannot at present be used for dyeing purposes on account of their insufficientaffinity to the fiber the coloring-matters obtained by heating the new compounds already mentioned with polysulfids show an excellent affinity to the fiber and are much faster than the products obtained from amidooxydipheuylamin.

The method of producing the amidotolyloxyphenylamin is illustrated by the following example: Eleven kilos para amidophenol and 10.7 kilos ortho toluidin are dissolved in two hundred liters Water and thirty-one kilos sulfuric acid, (66 Baum.) The solution is well cooled with ice and quickly mixed with a solution of twenty kilos bichromate of soda and two hundred liters water. A concentrated solution of seventy-five kilos sodium sulfid is at once added and the whole heated by means of direct steam to from to Centigrade. The para amidotolyl para oxyphenylamin goes into solution, whereas the chromium hydrate remains undissolved. The hot solution isfiltered and the base separated from the cooled filtrate by the addition of bicar' bonate of soda. The separation may be completed by saturation with common salt. In order to purify the product thus obtained, it is dissolved in dilute hydrochloric acid and precipitated from the filtered solution by the addition of carbonate of soda. The base thus obtained is easily soluble in water in presence of mineral acids or alkalies and in alcohol, but somewhat more difficultly in benzene, crystallizing out from this latter solvent in the shape of grayish-white needles, melting at 160 ceutigrade.

Themethod of producing ablue sulfurdyestufl' from the ainidotolyloxyphenylainin is illustrated by the following example: Forty eight kilos crystallized sodium sulfid are melted in an iron vessel connected with a refluxcondenser. eleven kilos para ainidotolyl para oxyphenyllamin are added, successively, while the tempera ure is about 80 centigrade. The temperature is then raised to 120 centigrade and maintained at that point for about twenty hours. The leuco compound of the (lyestuff is dissolved in the melt, from the solution of which'the dyestuff itself may be separated by introducing a current of air. The dyestuif is easily soluble in water in presence of sodium sulfid with a reddish-purple color and dyes direct indigo-blue shades on unmordanted cotton. By modifying the conditions of melting the shade of the coloring-matters may be varied. At higher temperatures dyestuffs of a more greenish and duller shade are obtained, While at lower temperatures or if working in an alcoholic solution more reddish and brighter shades. The general properties of the dyestuffs, however, remain essentially the same.

Having thus described my invention and in what manner the same can be performed, What I claim is- 1. The process of producing blue cotton Then nineteen kilos sulfur and dyestuffs by heating para amidotolyl para presence of caustic alkalies or sulfids with a reddish-purple color, soluble in concentrated sulfuric acid with adark-blue color and which dyes unmordanted cotton in a bath contain- 5 ing alkaline snlfids blue shades fast to acids, Witnesses:

milling and light substantially as described. JEAN GRUND, Signed at Frankfort-on-the-Main, in the l CARL GRUND.

Province of Hesse-Nassau and Kingdom of Prussia, this 17th day January, A. D. 1902.

RICHARD HERZ. 

